Alternate action mechanism with driving member movable out of engagement with latching channel in unlatched position

ABSTRACT

A pushbutton switch of the type actuated by a push-push motion of a control member is provided with a compact miniaturized structure having means to facilitate smooth operation with a minimum of frictional resistance and at the same time to provide a sharp and reliable switching action. The switch body is provided with a generally heart-shaped channel adapted to receive the upstanding end of a driving member which in turn is carried by a push rod slidable into and out of the switch body between its two operative positions. The channel is stepped to provide positive snap action switching and means are provided to impart a seesaw motion to the driving member, thereby to move the upstanding end thereof into positive camming engagement with the stepped upper surface of the channel, yet to maintain that upstanding end spaced from the upper surface of the channel over a substantial portion of its operating path. Means are provided on the switch body for engaging the driving member first on one side and then at the other side of the pivotal support projection thereby to bias the upstanding end of the driving member into and out of engagement with the stepped channel surface as the push rod is moved between its two operative positions.

United States Patent Ohkita Oct. 10, 1972 [54] ALTERNATE ACTION MECHANISM WITH DRIVING MEMBER MOVABLE OUT OF ENGAGEMENT WITH' LATCHING CHANNEL IN UNLATCHED POSITION [72] lnventor: Masao Ohkita, Tokyo, Japan [73] Assignee: Alps Electric Co., Ltd., Tokyo,

Japan' [22] Filed: Oct. 21, 1971 [21] Appl. No.: 191,327

[30] Foreign Application Priority Data March 27, 1971 Japan ..46/l8269 [52] US. Cl. ..200/l53 .1, 74/99 R [51] Int. Cl. ..l-I0lh 13/56 [58] Field of Search ..200/l53 J, 169 PB, 166 SD, 200/67 G; 74/99 R, 99 A, 527

[56] References Cited UNITED STATES PATENTS 1,941,252 12/1933 Douglas ..200/67 G UX 2,978,555 4/1961 Jones ..200/l53 J FOREIGN PATENTS OR APPLlCATIONS 1,164,260 9/1969 Great Britain ..200/l53 J 1,295,048 5/1969 Germany ..200/l53 .1

Primary Examiner--Robert K. Schaefer Assistant ExaminerRobert A. Vanderhye Attorney-Maxwell James et al.

[ 7] ABSTRACT A pushbutton switch of the type actuated by a pushpush motion of a control member is provided with a compact miniaturized structure having means to facilitate smooth operation with a minimum of frictional resistance and at the same time to provide a sharp and reliable switching action. The switch body is provided with a generally heart-shaped channel adapted to receive the upstanding end of a driving member which in turn is carried by a push rod slidable into and out of the switch body between its two operative positions. The channel is stepped to provide positive snap action switching and means are provided to impart a seesaw motion to the driving member, thereby to move the upstanding end thereof into positive camming engagement with the stepped upper surface of the channel, yet to maintain that upstanding end spaced from the upper surface of the channel over a substantial portion of its operating path.

Means are provided on the switch body for engaging the driving member first on one side and then at the other side of the pivotal support projection thereby to bias the upstanding end of the driving member into and out of engagement with the stepped channel surface as the push rod is moved between its two operative positions.

16 Claims, 10 Drawing Figures PATENTEDBBI 10 m2 SHEET 1 BF 3 INVENTOR.

$540 ax/mm ALTERNATE ACTION MECHANISM WITH DRIVING MEMBER MOVABLE OUT OF ENGAGEMENT WITH LATCHING CHANNEL IN UNLATCHED POSITION This invention relates to a pushbutton switch and more particularly to a switch of the type actuated by a push-push motion of a control member.

In switches of this type, a first push on the control button is effective to cause the push rod to move from an outer to an inner position and to remain in that position until the button is again pushed, whereupon the push rod will be released from its inner position and returned to its outer position.

In the past, structures of this type have proved somewhat unsatisfactory in several important respects. Typically in the design of these structures the push rod of the switch is provided with a substantially heart shaped channel and a cooperating driving member counted on the switch housing is received within said channel. The heart-shape of the channel defines two stable positions for the driving member, that member being spring biased into one of those two stable positions upon actuation of the push rod. To ensure that the driving member is moved fully from one to the other of its stable positions without springback upon actuation of the push rod, the channel is typically provided with one or more steps on its bottom surface and the driving member is spring urged into camming detent engagement with that channel surface. A particular advantage of this arrangement is that by moving the driving member over the step in the channel, it positively prevents snapback once the push rod is moved the required distance. Moreover, this design results in a sharp switching action which provides a decisive feel to the operator.

On the other hand, this design has three rather'major drawbacks. First, the driving member typically extends above the body of the switch, thereby causing the switch to occupy a larger space than desired. Second, because the driving member extends above the switch housing and must swing from side to side within the heart-shaped channel the switch housing must be relieved in order to permit the required movement. Third, and perhaps most importantly, the action of the camming spring causes maximal frictional engagement between the push rod and the channel surface, thereby severely restricting smooth operation. Indeed, this design often causes a severe biting action between the driving member and the channel surface which in turn results in operational failure of the device.

In my copending application Ser. No. 24,656, filed Apr. 1, 1970 entitled Push-Push Type Switch and assigned to the assignee of this application, I disclose an improved switch of the type described which substantially eliminates the aforementioned drawbacks. That switch utilizes a driving member which is swingably mounted on the push rod for movement therewith. A heart-shaped channel is provided in the underside of the switch housing and receives an upstanding end of the driving member, that upstanding end traversing the channel as the push rod is actuated. The driving member is supported along substantially its entire length by the push rod and is spring biased into engagement therewith, whereby the upstanding end thereof is maintained spaced from the top wall of the channel, effective movement between its two stable positions being provided by the shape of the channel itself.

Accordingly, that switch is relatively compact, provides only a minimum of frictional resistance to actua tion and utilizes an unweakened switch housing. However, that switch design, while admittedly eliminating the aforementioned problems, itself has been found somewhat unsatisfactory, particularly as regards reliability of operation. Thus as a result of the lack of any camming steps on the channel surface, the desirable sharp switching action and resulting feel are absent. Moreover, during each switch actuating, the free end 'of driving member must traverse a rather serpentine path within the channel to move from one of its stable positions at the point of the heart to the other at the cleavage in response to a unidirectional push on the control button. That free end must be steered by the outer wall of the channel beyond the edge of the inner wall prior to release of the pushbutton if the switch is to be effectively locked in that other position. Premature release of the pushbutton or a slight reverse swinging motion of the driving pin upon release of the button will result in a snapback to the original switch position. As a result rapid or careless actuation of the pushbutton is often ineffectual to provide the desired switching action.

It is a primary object of the present invention to provide a pushbutton switch of the type described which substantially eliminates all of the aforementioned drawbacks.

It is another object of the present invention to provide a pushbutton switch of the push-push type having a compact miniaturized structure utilizing an unweakened housing and characterized by a smooth operation with a minimum of frictional resistance, yet providing a sharp and reliable switching action.

It is a further object of the present invention to provide a pushbutton switch of the type described characterized by a two-step operation incorporating a substantially friction-free operation over a substantial portion of the operating path of the driving member yet providing a stepped camming or detent action to provide for sharp and reliable switching.

It is still another object of the present invention to provide a pushbutton switch of the type under discussion which is inexpensive to manufacture, easy to assemble and extremely reliable in operation.

To these ends, the switch of the present invention comprises a housing with an essentially heart-shaped channelon an inner surface of a wall thereof in opposing relationship to the upper surface of the push rod, that channel being suitably stepped to provide sharp camming switch action. The upper surface of the push rod is provided with a fan-shaped recess within which a driving member is received. That driving member is preferably in the form of an elongated Z-shaped pin having a downtumed portion at one end pivotally received in an opening in the push rod and an upturned portion at its other end received in the housing channel. The fan-shaped recess in the push rod is provided with an elongated projection extending transversely thereacross to provide a pivotal support for the elongated portion of the drive pin. Means are provided on the housing to resiliently bias the drive pin towards the push rod, that bias means cooperating with the aforementioned pivot support projection to impart a seesaw motion to the drive pin upon movement of the push rod between its two operative positions. As a result, the upturned end of the drive pin is normally biased out of engagement with the top wall of the channel in the outer position of the push rod but is pivoted into engagement therewith as it approaches the stepped portion thereof to provide the desired camming action for switching to the inner position of the push rod. Upon a subsequent actuation of the push rod a second camming operation is effective to unlock the drive pin from its inner position whereupon the push rod commences its return to the outer position. That return is facilitated by seesaw motion of the drive pin which is effective to moveits upturned portion out of contact with the upper wall of the channel at the beginning of such return movement, thereby to substantially eliminate frictional resistance.

In one embodiment an additional support projection is provided at the wide end of the fan-shaped recess, that projection being provided with inclined surfaces adapted to cooperate with the resilient bias means to ensure the desired seesaw motion of the drive pin. In another embodiment, the pivotal support projection on the push rod is replaced by a similarly located, op-

positely facing projection on the drive pin.

To the accomplishment of the above, the present invention relates to a pushbutton switch of the push-push type as defined in the appended claims and as described herein with reference to the accompanying drawings, in which:

FIG. 1 is a fragmentary perspective view of one embodiment of a pushbutton switch in accordance with the present invention, showing the push rod in its outer position;

FIG. 2 is a fragmentary exploded perspective view of the push rod and driving member of FIG. 1 showing the pivotal support projection;

FIG. 3A is a cross-sectional view taken generally along the line 3-3 of FIG. 1;

FIG. 3B is a cross-sectional view similar to FIG. 3A showing the push rod in its inner position with the drive pin pivoted into engagement with the top wall of the heart-shaped channel;

FIG. 4 is an enlarged fragmentary perspective view of the upper wall of the switch housing illustrated in an inverted position and showing the heart-shaped channel;

FIG. 5A is a schematic illustration in plan view of the heart-shaped channel showing the path traversed by the upstanding end of the driving member;

FIG. 5B is a schematic representation in section of the channel profile illustrating the camming steps;

FIG. 6A is a fragmentary perspective view of a second embodiment of a pushbutton switch in accordance with present invention;

FIG. 6B is a fragmentary exploded perspective view of the switch housing and biasing spring of the embodiment of FIG. 6A; and

FIG. 7 is a fragmentary exploded perspective view of the push rod and driving member of still another embodiment of the invention. 7

A first embodiment of my pushbutton is shown in perspective in FIG. 1. As there illustrated it comprises the conventional hollow housing or switch body 10 within which approximate fixed and movable switch contacts are mounted. (Those switch contacts form no part of the present invention and hence are not specifically disclosed.) The body 10 is provided with an opening 12 through which a push rod generally designated 14 extends. Push rod 14 is made of a suitable insulating material and is adapted to slide into and out of aperture 12 in the switch body, thereby to engage the appropriate switch contacts within. In the embodiment shown the push rod 14 is adapted to be moved to two operative positions and is normally biased to its outer position shown in. FIG. 1 by a suitable biasing spring 16 compressed between the body 10 and a stop member such as flange 18 secured to the push rod by appropriate means such as the groove 20. A second groove 22 may be provided on push rod 14 outwardly of flange 18 for mounting a suitable pushbutton on the free end 24 of the push rod.

As shown in broken lines in FIG. 1, the switch body 10 is provided with a generally heart-shaped channel 26 in the undersurface of its top wall 28, that channel facing the upper surface 30 of the push rod 14. A generally fan-shaped recess 32 is formed in that upper surface and carries a driving member generally designated 34. Driving member 34 is preferably in the form of a Z-shaped pin having an elongated bodyportion 34a, an upwardly directed portion 34b at one end and a downwardly directed portion 346 at its other end (see FIG. 2). The downwardly directed portion 34c is received in a circular notch 36 and the upstanding portion 34b (hereinafter referred to as the drive pin) is received in the channel 26 in the switch housing. The driving member 34 is thus adapted to move longitudinally with the push rod and to swing laterally within the fan-shaped recess 32 about the axis of the downwardly directed end 340.

As thus far described the switch is substantially identical to that disclosed in my aforementioned copending application, Ser. No. 24,656. In the prior construction there described and illustrated, the driving member was supported directly on the flat surface of the fan-shaped recess and means were provided for biasing the upstanding end of that member out of direct engagement with the upper wall of the housing channel. Upon actuation of the push rod, the upstanding end of the driving member was guided by the side walls of the housing channel from one to the other of its stable positions, without any frictional engagement between the driving member and the upper surface of the channel. As previously noted, while that structure significantly reduced frictional resistance and binding, the absence of detent stepping or positive snap action rendered the switch liable to faulty operation because of the lack of any positive feel on the part of the operator.

In the construction of the present invention, by contrast to that prior construction, the channel 26 is stepped to provide positive snap action switching and means are provided to impart a seesaw motion to the driving member 34, thereby to move the drive pin 34b of the driving member 34 into positive camming engagement with the stepped upper surface of channel 26, yet to maintain that pin spaced from the upper surface of that channel over a substantial portion of its operating path.

In the embodiment of FIG. 1 that seesaw motion imparting means comprises a generally rounded projection 38 formed on the surface of recess 32 and extending laterally thereacross. The main body portion 34a of driving member 34 is pivotally supported on that projection and is thus adapted to perform a seesaw movement between two operative positions, shown respectively in FIGS. 3A and 3B. A leaf spring 40 is mounted on the end of the switch body from which the push rod extends and extends downwardly into engagement with the elongated body 34a of the driving member 34.

As best shown in FIG. 3A that spring is preferably in the shape of a reversed S, one end of which is hookingly received in an L-shaped slot 42 in the upper wall 28 of the switch body and maintained therein by the compression spring 16. It will be apparent from the foregoing that the angular position of the driving member 34 in a vertical plane depends upon its point of engagement with the leaf spring 40 relative to the projection 38 defining its pivotal support. In accordance with the present invention, the projection 38 is so located that it passes from one side to the other of spring 40 as the push rod is moved between its two operative positions. Thus, as best shown in FIG. 3A, when the push rod 14 is in its outer position the leaf spring engages the driving member 34 to the left of the projection 38 whereby the driving member is pivoted counterclockwise to a position slightly tilted downwardly to the left. As illustrated, in this position, the drive pin 34b is biased out of engagement with the upper surface of channel 26. As the push rod is moved inwardly to the left (as viewed in FIG. 3A), the projection 38 passes under the leaf spring 40 to the right thereof and accordingly the driving member 34 pivots on projection 38 clockwise to a position tilted downwardly to the right as illustrated in FIG. 3B. In this position the drive pin 34b is urged into engagement with top surface of channel 26.

As best illustrated (in an inverted position) in FIGS. 4 and 5A the heart-shaped channel 26 provides two V- shaped receptacles 26a and 26b at the point and cleavage, respectively, which define the two stable positions of the drive pin 34b of driving member 34. The upper surface of the channel (viewed as the lower surface in FIGS. 4 and 5A) is provided with a first step 44 on one side of cleavage 26b comprising an inclined surface 44a extending in a direction away from the point 26a and terminating in a sharp edge 44b and a second step 46 comprising an inclined surface 46a extending from the cleavage area 26b and terminating in a sharp edge 46b. The path of the drive pin 34b of the driving member is shown schematically in FIG. 5A. In the outer position of push rod 14 (FIG. 3A) the drive pin 34b is at the point of the heart in the position designated A. As the push rod is moved inwardly (to the left in FIG. 3A) the pin 34b moves progressively in the direction indicated by the arrows to position B and thence as a result of its engagement with the side walls of the channel 26 to positions C and D. Upon release of the pushbutton the push rod is biased outwardly by coil spring 16 and pin 34b moves to position E and thence along the inner side wall of the channel to its stable inner position at the cleavage 26b designated F. When the button is again depressed, the pin 34b is moved into engagement with the outer side wall of the channel 26 and is guided by that side wall to position H. As the pushbutton is again released the coil spring 16 is effective to urge the pin 34b progressively to positions I and J and thence back to the stable outer position A at the point of the heart.

In accordance with the construction herein, a major portion of this path is traversed with pin 34b spaced from the top wall of the channel 26 in the position shown in FIG. 3A. The crossover to the position of FIG. 3B occurs at a point schematically illustrated by the broken line 48 in FIG. 5A. Thus, as the pin 34b reaches position B the projection 38 has moved to the left of leaf spring 40, the driving member 34 pivots clockwise and the pin 34b is urged into engagement with the inclined surface 44a of step 44. As the pin moves over the edge 44b to position C a sharp snap action results, that snap action providing the desired feel to the operator and in addition positively insuring against snap back to position A even if the button is release prematurely. Thus, if the button is released immediately following the snap of the pin over edge 44b, the pin will, as a result of the bias of spring 16, move directly to positions E and F without passing position D. Likewise, upon subsequent depression of the pushbutton the pin moves along the incline 46a to position G and snaps over the edge 46b to position I-I, edge 46b positively insuring against return to the inner position F. The detenting of pin 34b by steps 44 and 46 on the upper surface of the channel 26 is illustrated schematically by the cross sectional view of FIG. 55 (again in an inverted position).

Referring again to FIGS. 2-4, in accordance with the embodiment there shown, the seesaw motion of the driving member 34 is aided by a second projection 50 positioned at the wide end of the fan-shaped recess 32. Projection 50 is generally trapezoidal in shape and comprises a generally horizontal surface 50a and inclined surfaces 50b. As best shown in FIGS. 3A and 3B, those surfaces underlie the upstanding end 34b of driving member 34 and insure proper operation in the event leaf spring 40 loses resiliency or even fails.

Referring now to FIG. 6A, the embodiment there illustrated is provided with an improved leaf spring design which provides extremely reliable operation. In accordance with that embodiment the leaf spring 40 is provided with a pair of generally horizontal fingers 40a adapted to be received in grooves 52 in the undersurface of the switch body 10, a pair of arms 40b engaging the end of the switch body, and an outwardly extending cupping finger 40c adapted to engage one end of the coil spring 16. As will be apparent, the leaf spring may pivot slightly about the axis 54 and compression of coil spring 16 tends to urge the lead spring 40 downwardly into engagement with driving member 34. Accordingly, with this arrangement the leaf spring 40 may be constructed of a rather stiff material, proper operation thereby being insured over the lifetime of the device. In addition, as best shown in FIG. 6B, assembly and disassembly of the device is facilitated by this construction.

While the pivot means for driving member 34 is shown in FIG. 2 as a rounded projection 38 on the push rod 14, many other arrangements are of course possible. One such alternative is illustrated in FIG. 7 in which the bottom surface of the fan-shaped recess 32 is smooth and the Z-shaped driving member 34 is itself provided with a rounded projection 56 on its underside, that projection 56 engaging the bottom surface of recess32 to provide the required pivot action. In the embodiment illustrated, projection 56 is formed integral with driving member 34 merely by crimping that member at an appropriate location along its main body portion 34a.

In accordance with the above described construction, I have provided a pushbutton switch of the pushpush type which is inexpensive to manufacture and assemble, more reliable in operation, and provides desirable operating characteristics. The pushbutton switch herein described combines the desirable snap action of prior art devices with a generally smooth friction-free operation.

While only a limited number of embodiments of the present invention are hrein disclosed, it will be appreciated that many variations may be made without departing from the spirit and scope of the invention, as defined in the appended claims.

lclaim:

1. A pushbutton switch comprising a body with a surface, a channel in said surface, said channel having side walls and a bottom wall, a push rod movable relative to said surface in a given direction between first and second operative positions, a driving member carried by said push rod and having a part received in said channel, detent means on said bottom wall of said channel, and means active'on said driving member to urge said part toward said bottom wall of said channel and into engagement .with said detent means during a first portion of the travel of said part along said channel as it traverses said detent means and to urge said part out of engagement with said bottom wall of said channel during a second portion of its travel along said channel.

2. The pushbutton switch of claim 1, wherein said driving member is elongated, said part being disposed at one end thereof, said urging means comprising means for imparting a seesaw motion to said driving member in response to the movement of said push rod between its first and second positions.

3. The pushbutton switch of claim 2, in which said push rod is provided with a recess facing said body surface, said driving member being received in and said part of said driving member extending beyond said recess.

4. The pushbutton switch of claim 2, wherein said seesaw motion imparting means comprises means pivotally mounting said driving member for rotation about an axis substantially transverse to the direction of movement of said push rod and biasing means on said switch body engaging said driving member first at one side and then at the other side of said pivot axis as said push rod moves between its first and second operative positions.

5. The pushbutton switch of claim 4, in which said push rod is provided with a recess facing said body surface, said driving member being received in and said part of said driving member extending beyond said recess.

6. The pushbutton switch of claim 1, wherein said channel provides two stable positions for said part of said driving member received therein and wherein said detent means comprises first and second step means on either side of one of said stable positions of said part, said first step means being traversed by said part as it moves from one to the other of said stable positions and effective to prevent snapback of said part to said one stable position, said second step means being traversed as said part moves from said other stable position to said one stable position and effective to prevent snapback of said part to said other stable position.

7. The pushbutton switch of claim 3, wherein said recess is generally fan-shaped, said driving member being pivotally mounted at its other end at the narrow end of its recess.

8. The pushbutton switch of claim 5, wherein said recess is generally fan-shaped, said driving member being pivotally mounted at its other end at the narrow end of its recess.

9. The pushbutton switch of claim 6, wherein said seesaw motion imparting means comprises means pivotally mounting said driving member for rotation about an axis substantially transverse to the direction of movement of said push rod and biasing means on said switch body engaging said driving member first at one side and then at the other side of said pivot axis as said push rod moves between its first and second operative positions.

10. The pushbutton switch of claim 6, in which said push rod is provided with a recess facing said body surface, said driving member being received in and said part of said driving member extending beyond said recess.

11. The pushbutton switch of claim 10, wherein said seesaw motion imparting means comprises means pivotally mounting said driving member for rotation about an axis substantially transverse to the direction of movement of said push rod and biasing means on said switch body engaging said driving member first at one side and then at the other side of said pivot axis as said push rod moves between its first and second operative positions.

12. The pushbutton switch of claim 4, further com prising means urging said push rod in said given direction to one of said first or second positions, said push rod urging means operatively engaging said biasing means and being effective to urge said biasing means against said driving member as said push rod is moved to the other of said first or second positions.

13. The pushbutton switch of claim 12, in which said push rod is provided with a recess facing said body surface, said driving member being received in and said part of said driving member extending beyond said recess.

14. The pushbutton switch of claim 12, wherein said channel provides two stablepositions for said part of said driving member received therein and wherein said detent means comprises first and second step means on either side of one of said stable positions of said part, said first step means being traversed by said part as it moves from one to the other of said stable positions and effective to prevent snapback of said part to said one stable position, said second step means being traversed as said part moves from said other stable position to said one stable position and effective to prevent snapback of said part to said other stable position.

15. The pushbutton switch of claim 4, wherein said driving member comprises an elongated main body portion and wherein said pivotal mounting means comprises means projecting up from said recess, said main body portion of said driving member rockingly engaging said projecting means.

16. The pushbutton switch of claim 4, wherein said driving member comprises an elongated main body portion, and wherein said pivotal mounting means comprises means on said main body portion projecting rod. 

1. A pushbutton switch comprising a body with a surface, a channel in said surface, said channel having side walls and a bottom wall, a push rod movable relative to said surface in a given direction between first and second operative positions, a driving member carried by said push rod and having a part received in said channel, detent means on said bottom wall of said channel, and means active on said driving member to urge said part toward said bottom wall of said channel and into engagement with said detent means during a first portion of the travel of said part along said channel as it traverses said detent means and to urge said part out of engagement with said bottom wall of said channel during a second portion of its travel along said channel.
 2. The pushbutton switch of claim 1, wherein said driving member is eLongated, said part being disposed at one end thereof, said urging means comprising means for imparting a seesaw motion to said driving member in response to the movement of said push rod between its first and second positions.
 3. The pushbutton switch of claim 2, in which said push rod is provided with a recess facing said body surface, said driving member being received in and said part of said driving member extending beyond said recess.
 4. The pushbutton switch of claim 2, wherein said seesaw motion imparting means comprises means pivotally mounting said driving member for rotation about an axis substantially transverse to the direction of movement of said push rod and biasing means on said switch body engaging said driving member first at one side and then at the other side of said pivot axis as said push rod moves between its first and second operative positions.
 5. The pushbutton switch of claim 4, in which said push rod is provided with a recess facing said body surface, said driving member being received in and said part of said driving member extending beyond said recess.
 6. The pushbutton switch of claim 1, wherein said channel provides two stable positions for said part of said driving member received therein and wherein said detent means comprises first and second step means on either side of one of said stable positions of said part, said first step means being traversed by said part as it moves from one to the other of said stable positions and effective to prevent snapback of said part to said one stable position, said second step means being traversed as said part moves from said other stable position to said one stable position and effective to prevent snapback of said part to said other stable position.
 7. The pushbutton switch of claim 3, wherein said recess is generally fan-shaped, said driving member being pivotally mounted at its other end at the narrow end of its recess.
 8. The pushbutton switch of claim 5, wherein said recess is generally fan-shaped, said driving member being pivotally mounted at its other end at the narrow end of its recess.
 9. The pushbutton switch of claim 6, wherein said seesaw motion imparting means comprises means pivotally mounting said driving member for rotation about an axis substantially transverse to the direction of movement of said push rod and biasing means on said switch body engaging said driving member first at one side and then at the other side of said pivot axis as said push rod moves between its first and second operative positions.
 10. The pushbutton switch of claim 6, in which said push rod is provided with a recess facing said body surface, said driving member being received in and said part of said driving member extending beyond said recess.
 11. The pushbutton switch of claim 10, wherein said seesaw motion imparting means comprises means pivotally mounting said driving member for rotation about an axis substantially transverse to the direction of movement of said push rod and biasing means on said switch body engaging said driving member first at one side and then at the other side of said pivot axis as said push rod moves between its first and second operative positions.
 12. The pushbutton switch of claim 4, further comprising means urging said push rod in said given direction to one of said first or second positions, said push rod urging means operatively engaging said biasing means and being effective to urge said biasing means against said driving member as said push rod is moved to the other of said first or second positions.
 13. The pushbutton switch of claim 12, in which said push rod is provided with a recess facing said body surface, said driving member being received in and said part of said driving member extending beyond said recess.
 14. The pushbutton switch of claim 12, wherein said channel provides two stable positions for said part of said driving member received therein and wherein said detent means comprises first and second step means on either side of one of said stable positions of said part, said first step means being traversed by said part as it moves from one to the other of said stable positions and effective to prevent snapback of said part to said one stable position, said second step means being traversed as said part moves from said other stable position to said one stable position and effective to prevent snapback of said part to said other stable position.
 15. The pushbutton switch of claim 4, wherein said driving member comprises an elongated main body portion and wherein said pivotal mounting means comprises means projecting up from said recess, said main body portion of said driving member rockingly engaging said projecting means.
 16. The pushbutton switch of claim 4, wherein said driving member comprises an elongated main body portion, and wherein said pivotal mounting means comprises means on said main body portion projecting downwardly and adapted to rockingly engage said push rod. 